While Cliff's Edge is not Mexican food, its patio at Sunset & Edgecliffe is award-winning in the looks category, yet the food is also quite good.
El Conquistador across the street has decent Mexican food and a smallish, not great patio in front, yet not unlike the one at Malo up the street, both sort of good, but...
Cafe Pinot downtown LA adjacent to the Riordan Central Library has a fabulous garden setting if lighted hi-rise buildings might be your thing. Food decent enough, especially if you order carefully. Ciudad is also downtown and might also work.
I would say:
in north Glendale.
It is on the most quiet street around. The service is lovely the food is amazing bring a nice bottle of wine for a small corckage or order off their list.
It is not a "scene" but he food takes the stage.
There are 2 or 3 2 tops outside and the place is small enough that you will not be forgotten.
They do not bring the check until you ask for it...it's all about "no hurr, relax and take your time and enjoy your meal and your company."